I’m hoping that this really is the last col over 1000m on Vercors, within reach of Die, for me to document. It’s both the highest (at 1431m) and, starting at Pont-en-Royans, involves the biggest ascent (1181m).
But I should start by saying that the col itself is probably the most forgettable of the lot. Hidden in a dense wood, there are no views of, or from it. None whatsoever. However, it’s probably worth the effort (see below).
I should advise you to ascend from Pont-en-Royans and descend to Romeyère, for two main reasons. Firstly, the ascent to Presles is absolutely magnificent, and you need time to take in the unfolding drama, including the short bit of balcony, and short tunnels (visible from near the base of the climb). If you descend that bit, most of your concentration will be on keeping your bike on the road. Secondly, from Presles to the col is mostly a Route Forestière, and though unlike some it is tarmacked, it is frequently very gravelly, and would make a horrid descent. It’s fine as an ascent.
So, all that said, you might gather that it is a two-part climb: up to the tunnels, at about 800m, then, after a right turn before Presles, forest roads for about 10km and the other 631m of climbing. Watch out for the left fork shortly after the potable (and beautifully cool) Fountaine de Pétouse. (A picnicking family was cooling its wine in the trough today.)
The descent to Romeyère is unexciting (apart from a sudden splendid view, thanks to removed trees). Well, it would have been less exciting if, at the time of writing, the lower half of the descent hadn’t been liberally littered with potentially bike-eating potholes. Fortunately the quality of the road before that had already led me to plenty of caution!
So, in summary… if, like me, you like riding up hills, carry on up to the col. But if the extra 631m of climbing doesn’t entice you (and the prospect of descending the bottom half of Gorges de la Bourne, if you parked in Pont-en-Royans), then you can turn around at the tunnels. But that col will still be there…
The route: https://ridewithgps.com/routes/16205606